Extension of Aspiration Level Model for Optimal Planning of Fast Charging Stations

Electric vehicles will play a dominant role in future transportation due to their friendliness towards the present day environment. The battery which drives the vehicle can be refilled using battery charging and battery swapping techniques. Fast charging stations provide faster service to the customers. Though battery swapping method outperforms battery charging in many ways, the heavy infrastructure requirement of the former requires time in integrating with the real world. Queuing models are used to depict the real-time behavior of service stations. The aspiration level model provides the optimal value of charging piles for the given system capacity in a fast-charging station. The parameters in the aspiration level model can be formulated to an optimization problem. In the present work, the optimal planning for an fast charging station in Beijing is carried out using genetic algorithm. The simulation work is carried out in MATLAB/Simulink.

Design of Fast Charging Station with Energy Management for eBuses

The popularity of the eBus has been increasing rapidly in recent years due to its low greenhouse gases (GHG) emissions and its low dependence on fossil fuels. This incremental use of the eBus increases the burden to the power grid for its charging. Charging eBus requires a high amount of power for a feasible amount of time. Therefore, developing a fast-charging station (FCS) integrated with Micro Energy Grid (MEG) and hybrid energy storage is crucial for charging eBuses. This paper presents a design of FCS for eBus that integrates MEG with hybrid energy storage with the energy management system. To reduce the dependency on the main utility grid, a hybrid micro energy grid based on a renewable source (i.e., PV) have been included. In addition, hybrid energy storage of batteries and flywheels has also been developed to mitigate the power demand of the fast-charging station during peak time. Furthermore, a multiple-input DC-DC converter has been developed for managing the DC power transfer between the common DC bus and the multiple energy sources. Finally, an energy management system and the controller has been designed to achieve an extensive performance from the fast charging station. MATLAB Simulink has been used for the simulation work of the overall design. Different test case scenarios are tested for evaluating the performance parameters of the proposed FCS and also for evaluating its performance.